Protesters began the rally on Friday morning from the West Bank town of Zabuba west of Jenin, Aljazeera's correspondent reported.
Palestinians and members of the International Solidarity Movement have organised the rally expected to last for three weeks and end in a mass demonstration in Jerusalem.
Israel's concrete and steel barrier, which towers eight metres high at some points, cuts off some of the most fertile and water-rich areas of the West Bank. It also divides Palestinian villages and prevents thousands of farmers from reaching their land.
Israeli occupation forces slapped extra security measures in Zabuba in an effort to prevent Palestinians from participating in the rally, reported Aljazeera's correspondent Ali al-Samudi.
Tanks were stationed at the entrance of the town. However, many foreign volunteers were already in Zabuba on Thursday night and had gathered in the town's main square, said al-Samudi.
Demonstrators vowed that the barrier would be torn down and that the international community would stand by the Palestinians.
The ICJ ruled the 700km barrier
is a violation of international law
Participants also criticised Israel and its staunch ally, the United States, for not abiding by the International Court of Justice's (ICJ) ruling that Israel should tear down the wall because - according to the ICJ decision - it was a violation of international law.
Palestinians say the barrier is a land grab from the West Bank in exchange for Israel's planned unilateral withdrawal from the Gaza Strip and will demarcate the borders of a future state.
Israelis say the wall is necessary to keep out Palestinian resistance fighters waging an intifada against the continued occupation.
The barrier has also strained ties between Israel and the European Union after the EU's foreign policy and security chief Javier Solana scolded Israel for continuing the wall.
Elsewhere in the West Bank, 14 members of the Islamic Jihad and Hamas resistance groups were detained by Israeli soldiers in the Tulkaram refugee camp late on Thursday.
Occupation forces detained the activists during house raids, reported Aljazeera's correspondent.
In the occupied Gaza Strip, occupation soldiers shot dead four Palestinians allegedly on their way to plant a bomb near a fence separating Gaza from a Jewish settlement, according to Israeli Radio.
Palestinian medical officials said one man with shrapnel wounds had been treated but they were not aware of any deaths in the incident.
And the Izz al-Din al-Qassam Brigades said it had fired a number of rockets at the Jewish settlement of Sderot in Gaza, in a statement received by Aljazeera.
There were no reports of injuries. The group, the military wing of Hamas, said such incidents would continue despite Israel's siege on Bait Hanun.
The small city has been under a crippling blockade for over a month after Israeli troops sealed off the area. Israel says the siege is part of efforts to prevent Bait Hanun from being used as a launch pad to fire rockets.